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| Sunspot group AR1520 as it appeared July 11, 2012. Blame image softness on the photographer! |
Hosting a group of kids from Camp Asbury church camp this morning, we were treated to the best views of sunspots I’ve ever had. Sunspot group AR1520 is absolutely enormous, dominating the face of the Sun and observing conditions were very good. We could see good detail within the sunspots and where they merged along with some hints of granulation. We viewed the Sun at about 30X and, later, at 139X through Stephens Memorial Observatory’s 112-year-old 9-inch refractor fitted with a white light solar filter. We had 15 day campers (grades 1-6) and seven staff for a total of 22 people. I'm sure at least a few of them will remember AR1520 and our grand, old telescope for a long time to come! In the front yard we had our little hydrogen-alpha telescope set up. The views were less impressive but, if the viewer knew just what to look for, there were many prominences visible around the Sun's limb; old Sol is really active this summer!
After the campers left I hauled out my camera and discovered I had the wrong direct-focus adapter (1.25-inch instead of 2-inch) with me and could not focus at all! So I removed a piece to shorten the distance to the camera's focal plane, focused as best I could, and hand-held the camera at the open telescope tube for a direct-focus image. A yellow filter is in place within the camera adapter to try and keep the sensor clean. The resulting image is soft, not doing justice to the telescope or the sunspots, but the view is impressive nonetheless; it’s a good representation of what we saw, which was truly amazing!
Image Notes: Canon Digital Rebel XT: ISO 400, 1/1000 sec., yellow filter; handheld direct-focus image using 3,327mm refracting telescope (Warner & Swasey, circa 1901) with white-light solar filter by AstroZap.
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